The French president François Hollande, one of the only major western leaders scheduled to attend the Rio+20 Earth summit this week, will argue that sustainable development and the fight against poverty must be united in one agenda.

In an interview with the Guardian, Pascal Canfin, the new French development minister who will prepare the French negotiations in Rio, said: "We want one single agenda, to integrate sustainable development within the millennium development goals of poverty reduction. It's not about saying we'll replace the millennium goals with sustainable development goals.

"I know there are fears about that. It's about saying that in today's world, where the planet is at the limit of its ecosystem's capacity, the fight against poverty has to take into account environmental issues such as water, energy, urban development. "

While David Cameron and Angela Merkel are sending deputies and Barack Obama has yet to confirm, Hollande will fly to Rio on Wednesday, joining two French cabinet ministers. Asked whether France is seeking to take the lead while other western powers step back, Canfin said: "France is not there to take anyone else's place or speak in their name; we simply want it to be a success. We'll be in Rio because we want it to work."

Hollande, who has already warned against the risk of failure in Rio and "words that aren't met by actions", is under pressure to prove his environmental credentials in France and show the economic crisis has not knocked the environment and development off the agenda.

French presidents are famous for their soundbites at environment conferences – Jacques Chirac's impassioned speech in Johannesburg that "our house is on fire but we're looking the other way" still plays on a loop on French TV in the buildup to Rio +20. Hollande's former partner, then environment minister Ségolène Royal, attended the last Rio Earth summit while eight months pregnant with their fourth child because, she said, it was too important to miss.

But environmental groups warn the French government must follow through with concrete policy at home. Next month, Hollande, who was criticised by some environmentalists for a "lack of ambition" on green issues in his campaign, will launch a vast conference on the environment in France promising new laws. Nicolas Sarkozy's similar environmental conference was seen as producing little concrete after the former president first vowed to try to "save the human race" with a tax on carbon then abandoned the idea.

Canfin, 37, is one of two Green party figures that Hollande has brought in to cabinet with his Socialist party. An MEP, he previously founded an NGO, Finance Watch, to counter the weight of the financial lobby in the preparation of laws and regulations.

France's first demand at the Rio+20 conference is a precise date for the creation of a new UN environment agency to co-ordinate all the different parts, which France says should based in Nairobi.

Canfin said: "We're in a new era, a new moment in history where we know resources are limited. So we now have to define how we share those resources. It can no longer be along the lines, 'I take all and leave you nothing', or the rich take and there's no more left for the poor, or first come first served. We know international relations can sometimes be like that. But if we want to avoid growing tension we have to find a way around that, and the only framework is the UN multilateralism. Then we have to innovate in terms of production methods, consumption and new urban planning."

France is strongly pushing the notion of a green economy, arguing that in the economic crisis, reinventing the financial model is the only way out of the austerity trap. Canfin denied that the green economy was a Trojan horse for free market and big business. But he said companies needed to be at the centre of new technology while working within the framework of reducing inequality: "We need both dimensions. Those who swear by the green economy as simply technology and big business are wrong, they don't see the whole picture. Similarly those who only see the concept of the fight against poverty and the social dimension as it was constructed historically haven't understood the new order. That's why we're promoting both elements together."

France is to host a side event on so-called innovative financing, measures to bring in more aid revenues, including the divisive issue of a financial transaction tax (FTT), but not limited to the FTT alone. Canfin said France could learn from others, such as the UK, on vaccine initiatives and Germany on carbon.

He said the economic crisis should be seen as an opportunity for the environment: "It's in our interests as developed economies to go towards a green economy. If we abandon that we'll lose."

He acknowledged that since Copenhagen, arguments had been stuck in a rut but hoped they were starting to shift: "The danger is that the richest developed countries say we're in an economic crisis, we don't have the money to spend on this, so we make big speeches but behind it we neither engage in our own economic transition to a greener economy, nor put the means on the table.

"Then if the poorest countries say environmental change is nice idea but for the future, and the developing countries say our emerging middle class want to consume, if we don't move on those positions, if we don't contribute to ending them, everything is blocked. But I do feel there is a new awareness, particularly in the poorest countries, that environmental issues are not a luxury for tomorrow but a condition for today."

Hollande has tried to stay upbeat while acknowledging that the Rio+20 meeting is already being met with scepticism. "I know there's a pessimism around Rio's capacity to produce something," Canfin said. "That's why the French government won't give up, we won't leave Rio defeated. We know it's not an end-point in itself, but more of the opening of a process.

"But we mustn't be totally pessimistic either. It's the first time the question of the 'green economy', the transition of our world economic model, has been put on the table in such a clear way. It's the first international summit to headline on the green economy. It shows progress is being made, even if the path is difficult."